Uncontactless detection of improvised explosives TATP realized by Au NCs tailored PPV flexible photoelectric Schottky sensor.

Triacetone triperoxide (TATP) is widely used in terrorist attacks because of its simple synthesis but hard to be directly detected. Herein, polyphenylene vinylene (PPV) derivative with the vinyl group on the side chain is cross‐linked by Au nanoclusters (Au NCs) to construct flexible Schottky sensors to arrange the uncontactless detection of TATP vapor. Experiments and simulations show that Au NCs generate a strong electromagnetic field with collective coupling which can effectively promote the photoinduced electron‐hole separation of the PPV and detection sensitivity to TATP. The simple fingerprint patterns can discriminate TATP from 2,4,6‐trinitrotoluene (TNT), 2,4‐dinitrotoluene (DNT), p‐nitrotoluene (PNT), picric acid (PA), Hexogen (RDX), and tetryl by pattern to recognize inherent kinetics and thermodynamics of interaction between the sensors and specimen. The electron transfers from Au NCs to PPV after the adsorption of TATP molecules as the electronegativity of TATP is smaller than that of Au NCs and which is obvious in electron donating effect. Therefore, Au acts as a hole trap and reduces the hole concentration as well as restricting the carrier transport. However, the oscillator strength of the charge transferred from Au NCs to PPV simulation indicates that the role of Au NCs change from the hole trap to electron trap after adsorption of other explosives. Furthermore, the flexibility and stability of the sensor films are also demonstrated in this paper which is of great significance for the practical application of flexible electronic devices with high performance. [ABSTRACT FROM AUTHOR]